高得率浆制备育苗钵材料研究

以杨木BECMP为原料,加入适量湿强剂PAE,抄造新型可降解育苗钵,此育苗钵具有较好的物理特性,可用来替代塑料育苗钵,为育苗钵的研究开辟一条崭新的路线。通过实验确定了杨木BECMP抄造育苗钵较佳的工艺参数：PAE加入量为0.6%~0.8%,打浆度为40~50°SR。钵体降解试验表明,以杨木BECMP为原料抄造的育苗钵具...     

杨木挤压法漂白化机浆配抄性能研究

从与化学浆配抄时的加入比例,以及用BECMP代替PRC-APMP时的实验室模拟配抄角度,对杨木原料BECMP的配抄性能进行研究。结果表明:在与化学浆配抄时,少量加入杨木BECMP不会对成纸抗张强度产生重大影响;杨木BECMP可以替代PRC-APMP用于含机械浆类文化用纸的抄造。     

杨木挤压法漂白化机浆纤维形态电子显微镜分析

分别对杨木原料PRC-APMP和BECMP浆料进行扫描电子显微镜观察,从纤维分离程度、带状纤维数量、纤维弯曲及扭转状态、细胞壁形态变化等角度对两种浆进行对比分析,并结合成浆物理指标变化做出解释.研究结果认为:与APMP相比,BECMP磨浆强度可以达到甚至超过APMP水平;由于BECMP磨浆过程使纤维形态发生了有别于APMP的变化,内部细纤维化程度更高,纤维细胞壁微细纤维结构连接弱化甚至发生剥离,反映在成浆结合强度上抗张指数高于APMP,尤其随打浆度增高,差别幅度增大.     

杨木挤压法漂白化机浆成浆特性研究

分别对杨木原料PRC—APMP和BECMP浆料进行成浆特性分析,从制浆原料、成浆物理指标等角度对两种浆进行对比分析。研究结果认为：与APMP相比,BECMP成浆质量可以达到APMP成浆质量标准,抗张强度优于APMPo     

杨木BECMP抄造轻型纸纤维体系的研究

探讨在实验室条件下使用国产杨木挤压法漂白化机浆(BECMP)抄造轻型纸的纤维体系中,浆料的配比、打浆度等工程参数,并对各种浆料的作用进行研究。结果表明,该体系中漂白针叶木化学浆的最佳打浆度为55～57°SR,阔叶木化学浆最佳打浆度为32～35°SR;杨木BECMP的使用比例不宜高于84%;本研究条件下的最佳浆料比例为84%杨木BECMP、12%商品针叶木浆、4%商品阔叶木浆,该浆料比例手抄片抗张指数和松厚度可以达到轻型纸国家标准优等品质量要求。     

蔗渣基生物降解育苗杯应用于甘蔗组培苗种植上的应用效果研究

为了探讨蔗渣基生物降解育苗杯在甘蔗组培苗的应用效果,通过大田试验研究蔗渣基生物降解育苗杯的降解情况对组培苗生长的影响。结果表明,蔗渣基生物降解育苗杯能够满足甘蔗组培苗育苗的要求;杯苗同移后,蔗渣基生物降解育苗杯埋土后114天降解失重率为33.04%,到甘蔗组培苗砍收成蔗种时(埋土后200天)降解失重率为44.13%,此时杯体已完全破裂成碎片;蔗渣基生物降解育苗杯在甘蔗组培苗生长前期的降解过慢,甘蔗组培苗根系穿过杯体后快速生长,促进甘蔗组培苗生长及产量提高,到砍收作蔗种时,甘蔗增产率达18.38%。蔗渣基生物降解育苗杯基本符合甘蔗组培苗假植育苗与生长的需求,也具有显著的生态环保效果,但在土壤中前期降解稍慢,还需进一步调控与改进。     

蔗渣基生物降解育苗杯在水果玉米的应用效果研究

为了探讨蔗渣基生物降解育苗杯在水果玉米的应用效果,通过大田试验研究蔗渣基生物降解育苗杯的降解情况、对玉米育苗及生长的影响。结果表明,蔗渣基生物降解育苗杯能够满足玉米育苗的要求;杯苗同移后,蔗渣基生物降解育苗杯埋土后37天降解失重率仅为11.73%,到玉米收获时(埋土后54天)降解失重率为15.54%,但杯体已破裂成碎片;蔗渣基生物降解育苗杯在玉米生长前期的降解过慢,限制了玉米生长,后期玉米根系穿过杯体后生长能快速恢复,但还是导致玉米鲜穗产量显著减少。蔗渣基生物降解育苗杯基本符合玉米育苗与生长发育需求,也具有显著的生态环保效果,但在土壤中降解稍慢,还需进一步调控与改进。     

卷烟过滤嘴降解菌的筛选及其降解效果的电镜观察

从土壤和不同材料的堆肥中分离筛选高效稳定的纤维素分解菌,对一种改良卷烟过滤嘴材料进行降解,利用电子扫描显微镜来探讨该卷烟过滤嘴纤维素的降解过程与机理,初步了解该材料在环境中的降解行为,以便今后改进生产工艺,生产出更易于自然降解的过滤嘴材料。实验表明,这种改良材料在添加菌种的条件下,3 d降解率可达40%以上。     

杨木挤压法漂白化机浆与APMP化学组成的研究

采用化学分析手段,对杨木挤压法漂白化机浆（BECMP）与PRC-APMP化学组成进行了分析,并测定了成浆物理性能,分析不同制浆方法成浆化学组成与成浆物理性能的关系。结果表明：BECMP的1％NaOH抽出物、苯醇抽出物、Klason木素的溶出率较PRC-APMP大,碳水化合物溶出率较小,从而使成浆物理性能,尤其是纤维结合强度优于PRC-APMP。     

自水解后杨木边材木片化学组分和结构特性的变化及其对木片碱液浸渍的影响

分析了影响杨木边材木片对碱液反应性吸收的化学组分和结构特性在自水解预处理后的变化,及在碱液浸渍过程中浸渍液碱浓和浸渍温度对自水解木片浸渍效果的影响。结果表明,杨木边材木片的综纤维素、乙酰基和木素含量都随着自水解强度的增大而降低,而弱酸性基团含量则先增加后减少。在自水解预处理后,杨木导管内部的基质/侵填体得以清除,部分纹孔膜被溶解破坏。对原料木片及自水解预处理后杨木边材木片进行碱液浸渍处理后发现,木片的NaOH溶液吸收量和NaOH消耗量随自水解强度的增大而增加。自水解预处理改善了杨木边材木片的碱液浸渍效果。各类木片的NaOH溶液吸收量和NaOH消耗量均随浸渍液碱浓的增大和浸渍温度的升高而增加,且都呈现良好的线性相关性。     

Der Einfluß des Trocknungsgrades der Holzspäne auf die Festigkeit zementgebundener Spanplatten

Cement bonded particle boards were made of undried, air dried and kiln dried particles of spruce and poplar wood and the bending strengths of the boards were measured after 3, 10 and 28 days. Air dried particles of both wood species gave boards with better strength properties than undried particles. Kiln drying of the particles was found to have a substantially improving effect on the bending strength of cement bonded particle boards made of poplar particles whereas the same procedure did not produce any effect with spruce particles.     

双螺杆预浸渍磨浆机制浆性能研究

选取苏北地区不同品质的杨木加工剩余物为原料,采用一种我国自主研发出来的新型预浸磨浆系统以及常规的高浓盘磨对比研究不同品质杨木加工剩余物对化学机械法制浆性能的影响。研究结果表明:杨木加工剩余物的质量对制取化机浆的制浆得率、磨浆能耗、纸浆白度及纸浆的强度性能均有不同程度的影响。在相同H2O2用量为7.0%,NaOH用量6.0%条件下,以品质较好的杨木加工剩余物为原料,采用双螺杆新型预浸磨浆系统制得化机浆的得率可达85.6%左右,纸浆白度值81%ISO以上,在游离度为300mlCSF条件下,抗张强度可达到33N.m/g以上;以品质较差的杨木加工剩余物为原料,制浆得率为84.2%,纸浆白度为73%左右,抗张强度为29N.m/g。另外,采用双螺杆新型预浸磨浆系统比采用高浓盘磨制浆磨浆电耗上可节省30%左右,制浆得率、纸浆白度及纸浆的强度性能差异不大。     

酶法改善杨木APMP浆滤水性能的研究

分别采用纤维素酶和木聚糖酶处理杨木APMP浆,研究两种酶对浆料滤水性能的影响,同时考察其对纸浆强度的影响。研究结果表明,纤维素酶和木聚糖酶均能有效改善杨木APMP浆的滤水性能,同时纸浆的强度性能略有提高,且纤维素酶改善滤水性能效果要优于木聚糖酶。其中,纤维素酶改善杨木APMP浆滤水性能的最佳工艺为酶用量0.3U/g绝干浆、浆浓度1.0%、pH值4.5、温度45℃,时间60min;木聚糖酶改善杨木APMP浆滤水性能的最佳工艺为酶用量1.5U/g绝干浆、浆浓度0.5%、pH值7.0、温度45℃,时间30min。     

Formation and degradation kinetics of the biofumigant benzyl isothiocyanate in soil

Glucosinolates (GSLs) are produced by plants of the Capparales order. Upon enzymatic hydrolysis the GSLs can be transformed to the toxic isothiocyanates (ITCs), which can be used as biofumigants for the control of soil-borne pests. The rates of ITC formation and degradation are critical to both biofumigation and the toxicity and leaching of GSLs and ITCs in soil. Degradation kinetics of benzyl GSL and benzyl ITC in a sandy and clayey surface and subsoil at 8-9 degrees C at natural moisture contents were investigated, as was the rate of formation of ITC from the GSL. Degradation of GSL followed logistic kinetics with t 1/2 = 0.7-9.1 days. Degradation was faster in clayey soil compared to sandy soil, and faster in surface soil compared to subsoil. In surface soils, up to 25% of added GSL was detected as ITC, while only 1-6% were detected in the subsoils. ITC degradation followed first-order kinetics with t 1/2 = 0.3-1.7 days, with faster degradation in subsoils than in surface soils. Based on the data for GSL hydrolysis and ITC degradation, the concentration of ITC following GSL application was successfully modeled assuming complete conversion of glucosinolate to isothiocyanate and first-order degradation of isothiocyanate.     

烟稻轮作田土壤中二氯喹啉酸残留阈值分析

为明确烟稻轮作田土壤中二氯喹啉酸导致烟草药害的残留阈值,研究了稻田不同施药剂量下二氯喹啉酸的残留量和降解规律,分析了残留量和烟草药害等级相关性。结果表明,土壤中较低浓度的二氯喹啉酸残留就可导致烟草药害。稻田推荐剂量的二氯喹啉酸在植烟土壤中半衰期为25.7 d,施用60 d后降解率为77.83%。移栽后60 d,土壤中二氯喹啉酸残留量与烟草药害等级呈指数关系,残留阈值为0.006 mg/kg,如超过此阈值,烟草会产生明显药害症状。烟田规划期即烟草移栽前60 d,二氯喹啉酸残留风险值为0.072 mg/kg。研究为控制二氯喹啉酸药害风险和烟田规划提供了理论依据和数据支撑。     

Bioaccessibility of environmentally aged 14C-atrazine residues in an agriculturally used soil and its particle-size aggregates

After 22 years of aging under natural conditions in an outdoor lysimeter the bioaccessibility of 14C-labeled atrazine soil residues to bacteria was tested. Entire soil samples as well as sand-sized, silt-sized, and clay-sized aggregates (>20, 20-2, and <2microm aggregate size, respectively) were investigated under slurried conditions. The mineralization of residual radioactivity in the outdoor lysimeter soil reached up to 4.5% of the total 14C-activity after 16 days, inoculated with Pseudomonas sp. strain ADP. The control samples without inoculated bacteria showed a mineralization maximum of only about 1% after 44 days of incubation. Mineralization increased in the clay-sized aggregates up to 6.2% of the total residual 14C-activity within 23 days. With decreasing soil aggregate sizes, residual 14C-activity increased per unit of weight, but only minor differences of the mineralization in the soil and soil size aggregates using mineral-media for incubation was observed. Using additional Na-citrate in the incubation, the extent of mineralization increased to 6.7% in soil after 23 days following incubation with Pseudomonas sp. strain ADP. These results show that long-term aged 14C-atrazine residues are still partly accessible to the atrazine degrading microorganism Pseudomonas sp. strain ADP.     

Halbzellstoffe nach dem NSSC-Verfahren aus Pappelholz

Semi-chemical pulps from poplar wood of different clones, sites and ages were prepared according to the NSSC-method. The results reveal: Poplar semi-chemical pulps show higher strength properties than industrial as well as laboratory made NSSC-pulps from beech wood. However, the pulping conditions have to be optimized for every clone. Under used pulping conditions semi-chemical pulps from the clone “Scott Pauley” were of lower strength properties compared to those of other clones. The results show clearly that for the buildup of the strength properties the site is by far more important than the age of the trees used for pulping. Semi-chemical pulps obtained from different height levels show wide differences in their mechanical properties. Bark content up to 15% has no significant influence on the mechanical properties of NSSC-pulps from poplar wood but on their yield.